Autism
Autism, also known as autism spectrum disorder, is a condition characterized by differences or difficulties in social communication and interaction, a need or strong preference for predictability and routine, sensory processing differences, focused interests, or repetitive behaviors. Features of autism are present from early childhood and the condition typically persists throughout life. Autism is classified as a neurodevelopmental disorder, and a formal diagnosis requires professional assessment that these characteristics cause significant challenges in daily life beyond what is expected given a person's age and social environment. Because autism is a spectrum disorder, presentations vary and support needs range from minimal to the person being non-speaking or needing 24-hour care.
Autism diagnoses have risen since the 1990s, largely because of broader diagnostic criteria, greater awareness, and wider access to assessment. Changing social demands may also play a role. The World Health Organization estimates that about 1 in 100 children were diagnosed between 2012 and 2021, noting an increasing trend. Surveillance studies suggest a similar share of the adult population would meet diagnostic criteria if formally assessed. Autism is highly heritable and involves many genes, while environmental factors appear to play a smaller, mainly prenatal role. Boys are diagnosed several times more often than girls, with girls being better at hiding autistic traits. Conditions such as anxiety, depression, attention deficit hyperactivity disorder, epilepsy, as well as intellectual disability, are more common among autistic people. Certain savant abilities are also more common in autistic people than in other groups.
There is no cure for autism. Several autism therapies aim to improve self-care, social, and language skills. Reducing environmental and social barriers helps autistic people participate more fully in education, employment, and other aspects of life. No medication addresses the core features of autism, but some are used to help manage commonly co-occurring conditions, such as anxiety, depression, irritability, ADHD, and epilepsy.
Autistic people are found in every demographic group and, with appropriate supports that promote independence and self-determination, can participate fully in their communities and lead meaningful, productive lives. The idea of autism as a disorder has been challenged by the neurodiversity framework, which frames autistic traits as a healthy variation of the human condition. This perspective, promoted by the autism rights movement, has attracted increasing research attention, but is debated and remains controversial among autistic people, advocacy groups, healthcare providers, and charities.
Signs and characteristics
Autism is primarily characterized by differences and difficulties in social interaction and communication, alongside restricted or repetitive patterns of interests, activities, or behaviors, and, in many cases, distinctive reactions to sensory input. The specific presentation varies widely. Clinicians often consider assessment for autism when these characteristics are present, especially if they are associated with difficulty obtaining or sustaining employment or education, difficulty initiating or maintaining social relationships, involvement with mental health or learning disability services, or a history of neurodevelopmental conditions or mental health conditions. In most cases, signs of autism are first observable in infancy or early childhood and remain throughout life. Autistic people may be significantly disabled in some respects, but average—or, in some cases, superior—in others.Social and communication skills
Autistic people may have differences in social communication and interaction, which can lead to challenges in environments structured around non-autistic norms. Current diagnostic criteria for autism require difficulties across three social domains: social-emotional reciprocity, nonverbal communication, and developing and maintaining relationships.Social–emotional reciprocity
Common early signs of autism include little or no babbling in infancy. Difficulties may also be apparent in traditional forms of reciprocal social interaction, such as games like peek-a-boo or pat-a-cake, as well as in shared attention to objects of interest. Historically, autistic children were said to be delayed in developing a theory of mind, and the empathizing–systemizing theory proposed that while autistic people may have compassion for others with similar autistic traits, they often have limited, though not necessarily absent, cognitive empathy. This may present as social naïvety, lower-than-average intuitive perception of the meaning or utility of body language, social reciprocity, or social expectations, including the habitus, social cues, and certain aspects of sarcasm, which to some degree may be influenced by co-occurring alexithymia.Recent research has increasingly questioned these earlier interpretations, as the double empathy problem theory proposes that misunderstandings arise mutually between autistic and non-autistic people, rather than solely from autistic deficits in empathy or social cognition. This perspective has contributed to a growing recognition that autistic behavior and communication may reflect different, rather than deficient, social behavior and communication styles. Autistic interests and conversational styles are often characterized by a strong focus on specific topics, a phenomenon known as monotropism.
Nonverbal communication
Autistic people often display atypical behaviors or differences in nonverbal communication. Some may make infrequent eye contact, even when called by name, or avoid it altogether because they find it uncomfortable, distracting, or overstimulating. They may recognize fewer emotions or interpret facial expressions differently, and may not respond with expressions expected by their non-autistic peers. They can also have difficulty inferring social context or subtext in conversation or text, resulting in different interpretations of meaning. Speech characteristics such as volume, rhythm, and intonation can vary, and atypical prosody is estimated to occur in at least half of autistic children.Developing and sustaining relationships
Signs of autism in childhood include less apparent interest in other children or caregivers, possibly with more interest in objects. Behaviors that may appear as indifference to non-autistic people often reflect autistic differences in recognizing others' personalities, perspectives, and interests. Most research has focused on interpersonal relationship difficulties between autistic and non-autistic people and on teaching social skills to address these gaps. But newer studies indicate that autistic people often form satisfying relationships with other autistic people, which can enhance quality of life.Children on the autism spectrum are more likely than their non-autistic peers to be involved in bullying, most often as victims. Among autistic people who seek friendships, reduced friendship quantity and quality are often associated with increased loneliness. Autistic people also face greater challenges in developing romantic relationships than non-autistic people.
Over time, many autistic people learn to observe and form models of social patterns, and develop coping strategies, such as "masking". Masking is associated with poorer mental health outcomes as well as delayed diagnosis, which can limit access to appropriate supports.
Restricted and repetitive behaviors
The second core feature of autism is a pattern of restricted and repetitive behaviors, activities, and interests. To be diagnosed with autism under the DSM-5-TR, a person must exhibit at least two of the following behaviors:- Repetitive behaviors: actions such as rocking, hand flapping, finger flicking, head banging, or repeating phrases or sounds. These behaviors may occur consistently or primarily when the person is stressed, anxious, or upset. They are also known as stimming. Other examples include playing with toys in ways others might consider limited or unusual.
- Resistance to change: a strong preference for routine, such as performing daily tasks in a specific order or showing distress in response to changes others may consider minor. The person may become distressed if their routine changes or is disrupted.
- Focused interests: intense interest in a particular activity, topic, or hobby, often accompanied by sustained attention and deep knowledge; for example, a strong attachment to certain objects or frequent discussion of a specific topic.
- Sensory reactivity: atypical responses to certain sensory inputs, such as aversion to specific sounds or textures, fascination with lights or movement, or apparent indifference to pain or temperature.